Phase I, dose-escalating, long-term AIDS Clinical Trial Group (ACTG) tolerance study of oral ganciclovir in HIV-infected infants, children and adolescents with asymptomatic CMV infection and low CD4 cell counts, and/or quiescent CMV disease. The study is designed to evaluate the pharmacokinetics and to determine pharmacokinetic parameters of the oral suspension of ganciclovir. Ganciclovir has been used intravenously for more than 10 years and is currently given to children intravenously for CMV disease. In a recent study, oral ganciclovir was safely given to adult AIDS patients and was shown to be useful in preventing or postponing CMV disease, but has never been given to children.